Glucocorticoids have anti-inflammatory properties and are widely used for the treatment of inflammatory disorders or diseases such as asthma and rhinitis. For examples, U.S. Pat. No. 4,335,121 discloses fluticasone propionate and derivatives thereof; WO 2002/012265 discloses a fluticasone derivative, fluticasone furoate, represented by formula I:

The chemical name of Compound I is 6α,9α-difluoro-11β-hydroxy-16α-methyl-17α-[(2-furoyl)oxy]-3-oxo-androsta-1,4-diene-17β-carbothioic acid S-fluoromethyl ester. The compound and fluticasone propionate were both developed by GlaxoSmitheKline. Based on the current studies, Compound I may be used for treating skin diseases, such as eczema, psoriasis, allergic dermatitis, neurodermatitis, pruritis, and hypersensitivity reactions; inflammatory conditions of the nose, throat, or lungs, such as asthma (including allergen-induced asthmatic reactions), rhinitis (including hayfever), nasal polyps, chronic obstructive pulmonary disease, interstitial lung disease, and fibrosis; inflammatory bowel conditions, such as ulcerative colitis and Crohn's disease; and auto-immune diseases, such as rheumatoid arthritis. The compound may also have use in the treatment of conjunctiva and conjunctivitis.
Methods for preparing the Compound of formula I are known. WO2002/012265 provides the following methods:
Method 1 provides that Compound IV reacts with bromofluoromethane or fluorochloromethane to obtain the target Compound I as follows:

Method 2 provides that Compound V undergoes a 9-carbon fluoridating reaction to obtain the target Compound I as follows:

Method 3 provides that 11-carbonyl group of Compound VI is reduced to obtain the target Compound I:
and
Method 4 provides that Compound VII reacts with a fluoride reagent to obtain the target Compound I, where in Compound VII, L represents a leaving group (e.g., a halide other than a fluoride, such as chloride, iodide, or sulphonate ester, such as mesylate, tosylate, or triflate).

In these methods, Method 1 is the only method that can be used for commercial production by reacting Compound IV with a fluoromethylating reagent to obtain the target Compound I.
Based on Method 1, WO 2007/144363 to GlaxoSmitheKline discloses the following reactions for making the Compound I:
a solution of Compound II in butanone with DMAP and tripropylamine is treated with furoyl chloride to obtain Compound III, which is then treated with N-methylpiperazine to de-fluoridize to obtain Compound IV. Compound IV is reacted with a fluoromethylating reagent to obtain the fluticasone furoate of Compound I. The method is performed in a homogeneous system, without isolating the Compounds III and IV, to obtain the final product of Compound I by a one-pot method.
These two methods are via the Compound IV, and reacting Compound IV with a fluoromethylating reagent to obtain Compound I. But Compound IV is unstable, hard to purify, thus the quality of Compound I is relatively low. Further, the preparation steps for Compound IV have disadvantages including more reaction steps, higher cost, more difficult to handle, and produces more industrial wastes.